Assessment of Correlation between Androgen Receptor CAG Repeat Length and Infertility in Infertile Men Living in Khuzestan, Iran

Background: The androgen receptor (AR) gene contains a polymorphic trinucleotide repeat that encodes a polyglutamine tract in its N-terminal transactivation domain (N- TAD). We aimed to find a correlation between the length of this polymorphic tract and azoospermia or oligozoospermia in infertile men living in Khuzestan, Iran.

Materials and methods: In this case-control study during two years till 2010, we searched for microdeletions in the Y chromosome in 84 infertile male patients with normal karyotype who lived in Khuzestan Province, Southwest of Iran. All cases (n=12) of azoospermia or oligozoospermia resulting from Y chromosome microdele- tions were excluded from our study. The number of CAG repeats in exon 1 of the AR gene was determined in 72 patients with azoospermia or oligozoospermia and in 72 fertile controls, using the polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis.

Results: Microdeletions were detected in 14.3% (n=12) patients suffering severe oligozoospermia. The mean CAG repeat length was 18.99 ± 0.35 (range, 11-26) and 19.96 ± 0.54 (range, 12-25) in infertile males and controls, respectively. Also in the infertile group, the most common allele was 19 (26.38%), while in controls, it was 25 (22.22%).

Conclusion: Y chromosome microdeletions could be one of the main reasons of male infertility living in Khuzestan Province, while there was no correlation between CAG length in AR gene with azoospermia or oligozoospermia in infertile men living in Khuzestan, Iran.